The summing function is discussed in the Doing Sums section of perlpacktut (not perlunpacktut, which does not exist) and in unpack, although it must be admitted that examples of counted-field summation in both these sources are a bit rare.

When putting a smiley right before a closing parenthesis, do you:

Use two parentheses: (Like this: :) )
Use one parenthesis: (Like this: :)
Reverse direction of the smiley: (Like this: (: )
Use angle/square brackets instead of parentheses
Use C-style commenting to set the smiley off from the closing parenthesis
Make the smiley a dunce: (:>
I disapprove of emoticons
Other